Signal skew is a well-known characteristic in high speed communications and video signal transmission. Signal skew also occurs in multiple twisted-pair cables that are prevalent today in computer networking. Generally speaking, skew is the mismatch in arrival times of data on different signal lines where the data was originally transmitted at the same time. Skew is caused by different propagation rates through different pairs of cable. This, in turn, in the case of twisted-pair cables, is typically caused by different twist rates for the pairs of signal lines. Paired signal wires that have a tighter twist rate cause the signals to propagate over a greater distance. Cables containing twisted pair wires are intentionally designed so that different pairs have different twist rates in order to reduce the cross talk between signal wire pairs.
Details of specifying delay lines are described in “Specifying Delay Lines,” by Lester Jacobson, Allen Avionics, Electronic Products Magazine, the contents of which are incorporated herein by reference.
U.S. Pat. No. 6,377,629, titled “Twisted Pair Communications Line System,” to Stewart et al., issued Apr. 23, 2002, the entire contents of which are incorporated herein by reference, illustrates a delay line formed by serpentine arrangements formed on two sides of a printed circuit board, e.g., FIG. 3 and column 9, line 24 to column 10, line 50 therein.